The United Nations has announced the establishment of a commission to investigate the 2007 assassination of Pakistan's former prime minister Benazir Bhutto.

Supporters of Benazir Bhutto have remained skeptical of the country's initial investigation that concluded al-Qaida or Taliban assassins most likely killed her in December 2007.

In July, officials of Ms. Bhutto's party appealed to the United Nations to form an independent commission to investigate.

U.N. Secretary General Ban Ki-moon said in Islamabad that after extensive consultation, a three-member commission will be created, "very soon." He spoke after meeting with Pakistani President Asif Zardari, the widower of Benazir Bhutto.

"This is a crime that shocked and offended the world," said Ban Ki-moon. "And I know this is a matter of great importance to the government and people of Pakistan."

When the former prime minister returned from exile in October 2007, she said she had received warnings from friendly intelligence agencies about several groups plotting to assassinate her.

The initial investigation by Pakistani authorities into the gun and suicide bomb attack that killed her after a political rally in Rawalpindi blamed Baitullah Mehsud, a Pakistani Taliban commander. U.S. intelligence officials also named him as the most likely suspect.

Her supporters have rejected those findings, suggesting that Ms. Bhutto's political opponents may have been involved and tampered with the investigation. British investigators later largely confirmed the initial findings, although admitted their access to evidence was limited.

Ms. Bhutto's widower Asif Zardari, now Pakistan's president, has resisted calls to conduct another Pakistani investigation. He said he hoped the independent, three-member U.N. commission will finally establish the facts and circumstances of her death.

"We believe that the commission's findings will lead to eventually exposing the financiers, the organizers, the sponsors and the conspirators of this terrorist act and bring them to justice," he said.